Continuous casting-continuous extrusion-continuous rolling short-process preparation method for high-copper alloy plate strip

Abstract

The invention relates to the technical field of copper alloy preparation and processing, and provides a continuous casting-continuous extrusion-continuous rolling short-process preparation method for a high-copper alloy plate strip, the high-copper alloy refers to that the total content proportion of alloy elements is within 5%, and the content proportion of copper elements is higher than 95%; wherein the alloy elements comprise and are not limited to nickel, silicon, cobalt, chromium, zirconium, iron, phosphorus, magnesium, zinc, tin and the like, the total amount of impurity elements is not greater than 0.01%, the oxygen content is not greater than 10PPm, and the hydrogen content is not greater than 1PPm; the specific preparation process comprises the following steps: up-drawing continuous casting; continuously extruding; cold rolling; and aging treatment. The preparation method has the advantages of low cost, low energy consumption, low emission, high uniformity and short process, and has advancement. The preparation technology of mainstream alloy plate strips such as copper-iron-phosphorus, copper-nickel-silicon and copper-chromium-zirconium is covered, systematicness, high coverage, advancement and innovativeness are achieved, and various high-copper alloy plate strip products with excellent performance can be efficiently prepared.

Description

Technical Field

[0001] The invention belongs to the technical field of copper alloy preparation and processing, and specifically relates to a short-process preparation method of high-copper alloy plate and strip continuous casting-continuous extrusion-continuous rolling. Background Art

[0002] With the rapid development of industries such as 5G communications, new energy, and artificial intelligence, high-performance copper alloys are widely used in the above fields due to their advantages such as good electrical conductivity, thermal conductivity, high elasticity, corrosion resistance, and easy forming. They have become important raw materials for manufacturing connectors, integrated circuits, various conductors and other key components. However, the existing copper strip preparation and processing problems such as long process, high efficiency, high cost, and poor uniformity limit the quality of copper alloy strips, making them unable to meet the needs of high-end fields. For this reason, the development of new short-process, high-uniformity preparation and processing technologies for high-copper alloys has become an urgent need, and it is also an important issue to break through the foreign technology blockade of high-end copper materials.

[0003] The existing copper alloy plate and strip preparation technology mainly adopts horizontal continuous casting or semi-continuous casting to obtain the billet, and then performs hot rolling, solution treatment and other processes, followed by cold rolling and aging treatment to obtain the product. The disadvantages of the existing process are: the initial ingot is large in size and large in tonnage, and there are problems such as poor uniformity of organization and composition, difficulty in preparation, and easy segregation; the hot rolling and solution treatment processes are high in energy consumption and cost, and the production cycle is long and the efficiency is low. The existing technology does not meet the future needs of low-carbon environmental protection, energy saving and cost reduction. Although there is also a continuous casting + continuous extrusion process, due to various technical reasons, only wire and pure copper plate and strip can be produced, and mass production of high-copper alloys cannot be achieved. To this end, the present invention proposes a short-process technology that can systematically produce and prepare high-copper alloy plates and strips. Summary of the invention

[0004] The purpose of the present invention is to propose a short-process preparation technology method for a high-copper alloy system, so as to realize the short-process preparation of high-copper alloy plates and strips with low cost, low energy consumption, low emissions and high uniformity.

[0005] In order to achieve the above object, the technical solution of the present invention is as follows: A short process preparation method of continuous casting-continuous extrusion-continuous rolling of high-copper alloy plate and strip, wherein the high-copper alloy refers to a high-copper alloy having a total alloy element content ratio of less than 5% and a copper element content ratio of more than 95%; wherein the alloy elements include but are not limited to nickel, silicon, cobalt, chromium, zirconium, iron, phosphorus, magnesium, zinc, tin, etc., the total amount of impurity elements is not more than 0.01%, the oxygen content is not more than 10 ppm, and the hydrogen content is not more than 1 ppm; The specific preparation process includes the following steps: (1) Upward continuous casting; (2) Continuous extrusion; (3) Cold rolling; (4) Time limit processing.

[0006] In (1) the continuous casting process is introduced: When the alloy composition contains high melting point and easily oxidized and burned elements such as chromium, zirconium, and iron, continuous feeding is used to ensure the uniformity of the composition. When the alloy composition contains low melting point and easily oxidized elements such as phosphorus, magnesium, zinc, and tin, they are added in the form of intermediate alloys, and the surface is covered with graphite flakes for protection. The cast rod is prepared by vacuum or non-vacuum continuous casting, with a diameter of 25-35mm, and the alloy surface is smooth and free of oxidation and cold shut; The macro grains of the cast rods are herringbone shaped or grow in a directional manner; The composition difference between the core and the edge of the cross section does not exceed 3%, and the composition difference between three random positions of the longitudinal section does not exceed 5%; The hardness range of the cast rod is between 60-110HV.

[0007] In (2) continuous extrusion process: The alloy slab is obtained by extruding using a continuous extrusion device, and the size range is 420mm-700mm in width and 12mm-18mm in thickness.

[0008] The temperature of the billet in the extrusion cavity during the continuous extrusion process meets the following requirements: when the alloy contains Cr and Zr, the temperature is not lower than 900°C; when the alloy contains Ni and Si, the temperature is not lower than 850°C; when the alloy contains Fe and P, the temperature is not lower than 800°C.

[0009] Water cooling or water mist cooling is adopted at the outlet of continuous extrusion billet, and the billet temperature is not lower than 750℃ when entering cooling.

[0010] The uniformity of the microstructure of the obtained continuously extruded slab meets the following requirements: the average grain size deviation in the longitudinal direction does not exceed 1%, the average grain size in the transverse direction does not exceed 5%, and the average grain size in the thickness direction does not exceed 3%; the overall average grain size of the extruded billet does not exceed 10μm.

[0011] The properties of the obtained continuous extruded billet meet the following requirements: when the alloy contains Cr and Zr, the hardness is not less than 100 HV and the conductivity is not higher than 60% IACS; when the alloy contains Ni and Si, the hardness is not less than 120 HV and the conductivity is not higher than 30% IACS; when the alloy contains Fe and P, the hardness is not less than 110 HV and the conductivity is not higher than 40% IACS.

[0012] In the (3) cold rolling and (4) aging steps: According to performance requirements, one, two or three cold rolling and aging treatments can be carried out.

[0013] The deformation of the continuous extruded billet in the first cold rolling shall not be less than 85%, the deformation of the second cold rolling shall not be less than 60%, and the deformation of the third cold rolling shall not be higher than 50%.

[0014] The aging temperature of the continuous extruded billet after cold rolling meets the following requirements: when the alloy contains Cr and Zr, the aging temperature is not higher than 400°C; when the alloy contains Ni and Si, the aging temperature is not higher than 350°C; when the alloy contains Fe and P, the aging temperature is not higher than 300°C.

[0015] After cold rolling + aging, the strip thickness is 0.1-0.5mm, with good mechanical and electrical properties and good bending performance.

[0016] The beneficial effects of the present invention are: First, the system proposes a short-process preparation technology method for high-copper alloy plates and strips with low cost, low energy consumption, low emissions and high uniformity, which is different from the existing copper plate and strip preparation technology and is more advanced. Secondly, the present invention covers the preparation technology of plates and strips of mainstream alloy series such as copper-iron-phosphorus, copper-nickel-silicon, copper-chromium-zirconium, etc., which can solve the key technical problems existing in the preparation process of this series of alloys, such as the difficulty in preparing the upper / lower guide rods, poor surface quality, high power in the continuous extrusion process, poor solid solution effect, poor uniformity of the organization, and lack of process matching strategy in the cold rolling aging process. It is systematic, highly covered, advanced and innovative, and can efficiently prepare various types of high-copper alloy plate and strip products with excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a flow chart of a short process preparation method of high copper alloy plate and strip continuous casting-continuous extrusion-continuous rolling; Figure 2 The organization diagram of the upward continuous casting rod and the continuous extrusion slab in Example 1; Figure 3 The organization diagram of the upward continuous casting rod and the continuous extrusion slab in Example 2; Figure 4 The organization diagram of the upward continuous casting rod and the continuous extrusion slab in Example 3; DETAILED DESCRIPTION

[0018] The embodiments of the present invention are further described in detail below with reference to the accompanying drawings.

[0019] Embodiment 1: A high copper alloy plate and strip continuous casting-continuous extrusion-continuous rolling short process preparation method, specifically a Cu-Fe-P alloy plate and strip continuous casting-continuous extrusion-continuous rolling short process preparation technology method, used in the fields of lead frames and connectors. The specific preparation method is as follows:

[0020] (1) Upward continuous casting The specific grades of the Cu-Fe-P alloy include C19400 and C19200, with a total impurity element content of 0.01%, an oxygen content of 5 PPm, and a hydrogen content of 0.1 PPm.

[0021] During the smelting process, Fe is added in the form of pure metal, P is added in the form of copper-phosphorus master alloy, and the surface is covered with graphite flakes for protection; the cast rod is prepared by non-vacuum upward continuous casting, with a diameter of 25 mm, a smooth alloy surface without oxidation and cold shut; the macroscopic grains of the cast rod are "herringbone"; the composition difference between the core and the edge of the cross section is 2%, and the composition difference at three random positions in the longitudinal section is 3%; the hardness range of the cast rod is 86HV.

[0022] (2) Continuous extrusion The Cu-Fe-P alloy slab with a width of 450 mm and a thickness of 16 mm was prepared on a TLJ630 continuous extruder using an upper guide rod. The billet temperature in the extrusion cavity during the continuous extrusion process was 800°C. Water cooling was used at the outlet of the continuous extrusion billet, and the billet temperature was 750°C when entering the cooling stage.

[0023] The average grain size deviation of the obtained continuous extruded slab along the longitudinal direction is 0.1%, the average grain size deviation along the transverse direction is 0.5%, and the average grain size deviation along the thickness direction is 1%; the overall average grain size of the extruded billet is 5μm. The obtained continuous extruded billet has a hardness of 108HV and a conductivity of 38%IACS.

[0024] (3) Cold rolling The continuous extruded billet is cold rolled, with the deformation of the first cold rolling being 89% and the second cold rolling being 89%. The deformation of the first cold rolling is 66%, and the deformation of the third cold rolling is 50%.

[0025] (4) Time limit The aging temperature of the continuous extruded billet after cold rolling is 300℃.

[0026] After two cold rolling + aging, 0.5mm strip was obtained with a tensile strength of 450MPa, a conductivity of 60%IACS and good bending performance.

[0027] Embodiment 2: A high copper alloy plate and strip continuous casting-continuous extrusion-continuous rolling short process preparation method, specifically a Cu-Ni-Si alloy plate and strip continuous casting-continuous extrusion-continuous rolling short process preparation technology method, used in the field of lead frames and connectors, the specific preparation method is as follows: (1) Upward continuous casting The specific grades of the Cu-Ni-Si alloy include C70250, C70260, and C70350, with a total amount of impurity elements of 0.01%, an oxygen content of 6 PPm, and a hydrogen content of 0.1 PPm.

[0028] During the upward continuous casting process, Ni, Si and Co elements are added in the form of pure metals, Mg and Zn elements are added in the form of intermediate alloys, and the surface is covered with graphite flakes for protection; non-vacuum upward continuous casting is used to prepare the cast rod, with a diameter of 25 mm, a smooth alloy surface without oxidation and cold shut; the macroscopic grains of the cast rod are in a "herringbone" shape; the composition difference between the core and the edge of the cross section is 2%, and the composition difference at three random positions in the longitudinal section is 1%; the hardness of the cast rod is 110HV.

[0029] (2) Continuous extrusion The alloy slab was prepared by using the upward continuous casting rod billet in the TLJ630 continuous extruder, with a size of 420 mm in width and 16 mm in thickness. The billet temperature in the extrusion cavity during the continuous extrusion process was 850°C, and water mist cooling was used at the outlet of the continuous extrusion billet, and the billet temperature was 800°C when entering the cooling.

[0030] The average grain size deviation of the obtained continuously extruded slab along the longitudinal direction is 0.6%, the average grain size deviation along the transverse direction is 1%, and the average grain size deviation along the thickness direction is 2%; the overall average grain size of the extruded billet is 5.5μm.

[0031] The obtained continuous extrusion billet has a hardness of 120HV and a conductivity of 30%IACS.

[0032] (3) Cold rolling The deformation of the continuous extruded billet in the first cold rolling is 90%, the deformation in the second cold rolling is 70%, and the deformation in the third cold rolling is 50%.

[0033] (4) Time limit The aging temperature of the continuous extruded billet after cold rolling is 350℃.

[0034] After two cold rolling + aging treatment, 0.5 mm strip is obtained with a tensile strength of 80 MPa and a conductivity of 41% IACS.

[0035] Embodiment 3: A high copper alloy plate and strip continuous casting-continuous extrusion-continuous rolling short process preparation method, specifically a Cu-Cr-Zr alloy plate and strip continuous casting-continuous extrusion-continuous rolling short process preparation technical method, the specific preparation method is as follows: (1) Upward continuous casting The specific grades of the Cu-Ni-Si alloy include C18150 and C18200, with a total impurity element content of 0.01%, an oxygen content of 8 PPm, and a hydrogen content of 0.5 PPm.

[0036] Cr is added to the alloy in the form of pure metal, Zr is added in the form of intermediate alloy, and continuous feeding is used to ensure uniform composition, and the surface is covered with graphite flakes for protection; the cast rod is prepared by non-vacuum upward continuous casting, with a diameter of 25 mm, a smooth alloy surface without oxidation and cold shut; the macroscopic grains of the cast rod grow in a "herringbone" shape; the composition difference between the core and the edge of the cross section is 3%, and the composition difference at three random positions in the longitudinal section is 3%; the hardness of the cast rod is 80HV.

[0037] (2) Continuous extrusion The alloy slab was prepared by TLJ630 continuous extruder with a width of 420 mm and a thickness of 16 mm. The temperature of the billet in the extrusion cavity during the continuous extrusion process was 900 °C. Water mist cooling was used at the outlet of the continuous extrusion billet, and the billet temperature was not less than 800 °C when entering the cooling. The average grain size deviation of the obtained continuous extrusion slab was 1% in the longitudinal direction, 4% in the transverse direction, and 3% in the thickness direction; the overall average grain size of the extruded billet was 6 μm.

[0038] The obtained continuous extrusion billet has a hardness of 100 HV and a conductivity of 56% IACS.

[0039] (3) Cold rolling The deformation of the continuous extruded billet in the first cold rolling is 93%, the deformation in the second cold rolling is 70%, and the deformation in the third cold rolling is 45%.

[0040] (4) Time limit The aging temperature of the continuous extruded billet after cold rolling is 400℃.

[0041] After two "cold rolling + aging" processes, the 0.5 mm strip has a tensile strength of 600 MPa and a conductivity of 80% IACS.

[0042] The embodiments described above are only preferred specific implementation methods of the present invention, and the protection scope of the present invention is not limited thereto. Any simple changes or equivalent replacements of the technical solutions that can be obviously obtained by any technician familiar with the field within the technical scope disclosed in the present invention belong to the protection scope of the present invention.

Claims

1. A high copper alloy plate and strip continuous casting-continuous extrusion-continuous rolling short process preparation method, characterized in that: The high-copper alloy refers to an alloy with a total content of less than 5% of alloy elements and a copper content of more than 95%; the alloy elements include but are not limited to nickel, silicon, cobalt, chromium, zirconium, iron, phosphorus, magnesium, zinc, and tin; the total amount of impurity elements is not more than 0.01%, the oxygen content is not more than 10 PPm, and the hydrogen content is not more than 1 PPm; The specific preparation process includes the following steps: (1) Upward continuous casting; (2) Continuous extrusion; (3) Cold rolling; (4) Time limit processing.

2. The high copper alloy plate and strip continuous casting-extrusion-rolling short process preparation method according to claim 1, characterized in that: In the upward continuous casting (1), when the alloy composition contains high melting point and easily oxidized and burned elements such as chromium, zirconium and iron, continuous feeding is adopted to ensure the uniformity of the composition; when the alloy composition contains low melting point and easily oxidized elements such as phosphorus, magnesium, zinc and tin, they are added in the form of intermediate alloy, and the surface is covered with graphite flakes for protection; The cast rod is prepared by upward continuous casting, with a diameter of 25-35mm, and the alloy surface is smooth and free of oxidation and cold shut; The macro grains of the cast rods are herringbone shaped or grow in a directional manner; The composition difference between the core and the edge of the cross section does not exceed 3%, and the composition difference between three random positions of the longitudinal section does not exceed 5%; The hardness range of the cast rod is between 60-110HV.

3. The high copper alloy plate and strip continuous casting-extrusion-rolling short process preparation method according to claim 2, characterized in that: In the continuous extrusion (2) described above, the alloy slab is obtained by extruding the alloy slab using the continuous extrusion equipment, and the size range is 420 mm to 700 mm in width and 12 mm to 18 mm in thickness; The temperature of the billet in the extrusion cavity during the continuous extrusion process meets the following requirements: when the alloy contains Cr and Zr, the temperature is not less than 900°C; when the alloy contains Ni and Si, the temperature is not less than 850°C; when the alloy contains Fe and P, the temperature is not less than 800°C; Water cooling or water mist cooling is used at the exit of continuous extrusion billet, and the billet temperature is not less than 750℃ when entering the cooling; The uniformity of the microstructure of the obtained continuously extruded slab meets the following requirements: the average grain size deviation in the longitudinal direction does not exceed 1%, the average grain size in the transverse direction does not exceed 5%, and the average grain size in the thickness direction does not exceed 3%; the overall average grain size of the extruded billet does not exceed 10μm; The properties of the obtained continuous extruded billet meet the following requirements: when the alloy contains Cr and Zr, the hardness is not less than 100 HV and the conductivity is not higher than 60% IACS; when the alloy contains Ni and Si, the hardness is not less than 120 HV and the conductivity is not higher than 30% IACS; when the alloy contains Fe and P, the hardness is not less than 110 HV and the conductivity is not higher than 40% IACS.

4. The high copper alloy plate and strip continuous casting-extrusion-rolling short process preparation method according to claim 2, characterized in that: In the above-mentioned (3) cold rolling and (4) aging treatment, (3) cold rolling and (4) aging treatment are carried out in combination, and the deformation amount of the continuous extruded billet in the first cold rolling is not less than 85%, the deformation amount of the second cold rolling is not less than 60%, and the deformation amount of the third cold rolling is not more than 50%; The temperature of aging treatment after cold rolling of the continuous extruded billet meets the following requirements: when the alloy contains Cr and Zr, the aging temperature is not higher than 400°C; when the alloy contains Ni and Si, the aging temperature is not higher than 350°C; when the alloy contains Fe and P, the aging temperature is not higher than 300°C; the thickness of the strip after cold rolling + aging is 0.1mm-0.5mm.

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